diff --git a/src/concurrency/ocf_cache_concurrency.c b/src/concurrency/ocf_cache_concurrency.c
index 9cfc88b..4b36776 100644
--- a/src/concurrency/ocf_cache_concurrency.c
+++ b/src/concurrency/ocf_cache_concurrency.c
@@ -795,9 +795,9 @@ static void _req_on_lock(void *ctx, uint32_t ctx_id,
 	if (env_atomic_dec_return(&req->lock_remaining) == 0) {
 		/* All cache line locked, resume request */
 		OCF_DEBUG_RQ(req, "Resume");
-		OCF_CHECK_NULL(req->resume);
+		ENV_BUG_ON(!req->io_if->resume);
 		env_atomic_dec(&c->waiting);
-		req->resume(req);
+		req->io_if->resume(req);
 	}
 }
 
@@ -806,7 +806,7 @@ static void _req_on_lock(void *ctx, uint32_t ctx_id,
  */
 int ocf_req_trylock_rd(struct ocf_request *req)
 {
-	OCF_CHECK_NULL(req->resume);
+	ENV_BUG_ON(!req->io_if->resume);
 	return _ocf_req_lock_rd_common(req, req, _req_on_lock);
 }
 
@@ -928,7 +928,7 @@ static int _ocf_req_lock_wr_common(struct ocf_request *req, void *context,
  */
 int ocf_req_trylock_wr(struct ocf_request *req)
 {
-	OCF_CHECK_NULL(req->resume);
+	ENV_BUG_ON(!req->io_if->resume);
 	return _ocf_req_lock_wr_common(req, req, _req_on_lock);
 }
 
diff --git a/src/concurrency/ocf_cache_concurrency.h b/src/concurrency/ocf_cache_concurrency.h
index bcd8223..3161c32 100644
--- a/src/concurrency/ocf_cache_concurrency.h
+++ b/src/concurrency/ocf_cache_concurrency.h
@@ -53,14 +53,14 @@ size_t ocf_cache_concurrency_size_of(struct ocf_cache *cache);
 /**
  * @brief Lock OCF request for WRITE access (Lock all cache lines in map info)
  *
- * @note req->resume callback has to be set
+ * @note io_if->resume callback has to be set
  *
  * @param req - OCF request
  *
  * @retval OCF_LOCK_ACQUIRED - OCF request has been locked and can be processed
  *
  * @retval OCF_LOCK_NOT_ACQUIRED - OCF request lock not acquired, request was
- * added into waiting list. When lock will be acquired req->resume be called
+ * added into waiting list. When lock will be acquired io_if->resume be called
  */
 int ocf_req_trylock_wr(struct ocf_request *req);
 
@@ -75,21 +75,21 @@ int ocf_req_trylock_wr(struct ocf_request *req);
  * @retval OCF_LOCK_ACQUIRED - OCF request has been locked and can be processed
  *
  * @retval OCF_LOCK_NOT_ACQUIRED - OCF request lock not acquired, request was
- * added into waiting list. When lock will be acquired req->resume be called
+ * added into waiting list. When lock will be acquired io_if->resume be called
  */
 int ocf_req_retrylock_wr(struct ocf_request *req);
 
 /**
  * @brief Lock OCF request for READ access (Lock all cache lines in map info)
  *
- * @note req->resume callback has to be set
+ * @note io_if->resume callback has to be set
  *
  * @param req - OCF request
  *
  * @retval OCF_LOCK_ACQUIRED - OCF request has been locked and can be processed
  *
  * @retval OCF_LOCK_NOT_ACQUIRED - OCF request lock not acquired, request was
- * added into waiting list. When lock will be acquired req->resume be called
+ * added into waiting list. When lock will be acquired io_if->resume be called
  */
 int ocf_req_trylock_rd(struct ocf_request *req);
 
diff --git a/src/engine/cache_engine.h b/src/engine/cache_engine.h
index 9b2eb59..63707b6 100644
--- a/src/engine/cache_engine.h
+++ b/src/engine/cache_engine.h
@@ -36,6 +36,8 @@ struct ocf_io_if {
 
 	int (*write)(struct ocf_request *req);
 
+	void (*resume)(struct ocf_request *req);
+
 	const char *name;
 };
 
diff --git a/src/engine/engine_common.c b/src/engine/engine_common.c
index d9ad484..ccba9a7 100644
--- a/src/engine/engine_common.c
+++ b/src/engine/engine_common.c
@@ -574,7 +574,6 @@ static int _ocf_engine_refresh(struct ocf_request *req)
 		/* Refresh successful, can process with original IO interface */
 		req->io_if = req->priv;
 
-		req->resume = NULL;
 		req->priv = NULL;
 
 		if (req->rw == OCF_READ)
@@ -601,14 +600,13 @@ static int _ocf_engine_refresh(struct ocf_request *req)
 }
 
 static const struct ocf_io_if _io_if_refresh = {
-		.read = _ocf_engine_refresh,
-		.write = _ocf_engine_refresh,
+	.read = _ocf_engine_refresh,
+	.write = _ocf_engine_refresh,
 };
 
 void ocf_engine_on_resume(struct ocf_request *req)
 {
 	ENV_BUG_ON(req->priv);
-	ENV_BUG_ON(ocf_engine_on_resume != req->resume);
 	OCF_CHECK_NULL(req->io_if);
 
 	/* Exchange IO interface */
diff --git a/src/engine/engine_discard.c b/src/engine/engine_discard.c
index f7973d4..d2b00db 100644
--- a/src/engine/engine_discard.c
+++ b/src/engine/engine_discard.c
@@ -22,25 +22,30 @@ static int _ocf_discard_step_do(struct ocf_request *req);
 static int _ocf_discard_step(struct ocf_request *req);
 static int _ocf_discard_flush_cache(struct ocf_request *req);
 static int _ocf_discard_core(struct ocf_request *req);
+static void _ocf_discard_on_resume(struct ocf_request *req);
 
 static const struct ocf_io_if _io_if_discard_step = {
 	.read = _ocf_discard_step,
-	.write = _ocf_discard_step
+	.write = _ocf_discard_step,
+	.resume = _ocf_discard_on_resume,
 };
 
 static const struct ocf_io_if _io_if_discard_step_resume = {
 	.read = _ocf_discard_step_do,
-	.write = _ocf_discard_step_do
+	.write = _ocf_discard_step_do,
+	.resume = _ocf_discard_on_resume,
 };
 
 static const struct ocf_io_if _io_if_discard_flush_cache = {
 	.read = _ocf_discard_flush_cache,
 	.write = _ocf_discard_flush_cache,
+	.resume = _ocf_discard_on_resume,
 };
 
 static const struct ocf_io_if _io_if_discard_core = {
 	.read = _ocf_discard_core,
-	.write = _ocf_discard_core
+	.write = _ocf_discard_core,
+	.resume = _ocf_discard_on_resume,
 };
 
 static void _ocf_discard_complete_req(struct ocf_request *req, int error)
@@ -263,9 +268,6 @@ int ocf_discard(struct ocf_request *req)
 	/* Get OCF request - increase reference counter */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = _ocf_discard_on_resume;
-
 	_ocf_discard_step(req);
 
 	/* Put OCF request - decrease reference counter */
diff --git a/src/engine/engine_fast.c b/src/engine/engine_fast.c
index 5d51e11..0bce983 100644
--- a/src/engine/engine_fast.c
+++ b/src/engine/engine_fast.c
@@ -102,8 +102,9 @@ static int _ocf_read_fast_do(struct ocf_request *req)
 }
 
 static const struct ocf_io_if _io_if_read_fast_resume = {
-		.read = _ocf_read_fast_do,
-		.write = _ocf_read_fast_do,
+	.read = _ocf_read_fast_do,
+	.write = _ocf_read_fast_do,
+	.resume = ocf_engine_on_resume,
 };
 
 int ocf_read_fast(struct ocf_request *req)
@@ -115,8 +116,7 @@ int ocf_read_fast(struct ocf_request *req)
 	/* Get OCF request - increase reference counter */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = ocf_engine_on_resume;
+	/* Set resume io_if */
 	req->io_if = &_io_if_read_fast_resume;
 
 	/*- Metadata RD access -----------------------------------------------*/
@@ -172,8 +172,9 @@ int ocf_read_fast(struct ocf_request *req)
  */
 
 static const struct ocf_io_if _io_if_write_fast_resume = {
-		.read = ocf_write_wb_do,
-		.write = ocf_write_wb_do,
+	.read = ocf_write_wb_do,
+	.write = ocf_write_wb_do,
+	.resume = ocf_engine_on_resume,
 };
 
 int ocf_write_fast(struct ocf_request *req)
@@ -185,8 +186,7 @@ int ocf_write_fast(struct ocf_request *req)
 	/* Get OCF request - increase reference counter */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = ocf_engine_on_resume;
+	/* Set resume io_if */
 	req->io_if = &_io_if_write_fast_resume;
 
 	/*- Metadata RD access -----------------------------------------------*/
diff --git a/src/engine/engine_pt.c b/src/engine/engine_pt.c
index 25304ed..9444421 100644
--- a/src/engine/engine_pt.c
+++ b/src/engine/engine_pt.c
@@ -99,6 +99,7 @@ int ocf_read_pt_do(struct ocf_request *req)
 static const struct ocf_io_if _io_if_pt_resume = {
 	.read = ocf_read_pt_do,
 	.write = ocf_read_pt_do,
+	.resume = ocf_engine_on_resume,
 };
 
 int ocf_read_pt(struct ocf_request *req)
@@ -114,8 +115,7 @@ int ocf_read_pt(struct ocf_request *req)
 	/* Get OCF request - increase reference counter */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = ocf_engine_on_resume;
+	/* Set resume io_if */
 	req->io_if = &_io_if_pt_resume;
 
 	OCF_METADATA_LOCK_RD(); /*- Metadata RD access -----------------------*/
diff --git a/src/engine/engine_rd.c b/src/engine/engine_rd.c
index 022ae5c..50be1d9 100644
--- a/src/engine/engine_rd.c
+++ b/src/engine/engine_rd.c
@@ -206,8 +206,9 @@ static int _ocf_read_generic_do(struct ocf_request *req)
 }
 
 static const struct ocf_io_if _io_if_read_generic_resume = {
-		.read = _ocf_read_generic_do,
-		.write = _ocf_read_generic_do,
+	.read = _ocf_read_generic_do,
+	.write = _ocf_read_generic_do,
+	.resume = ocf_engine_on_resume,
 };
 
 int ocf_read_generic(struct ocf_request *req)
@@ -228,7 +229,6 @@ int ocf_read_generic(struct ocf_request *req)
 	ocf_req_get(req);
 
 	/* Set resume call backs */
-	req->resume = ocf_engine_on_resume;
 	req->io_if = &_io_if_read_generic_resume;
 
 	/*- Metadata RD access -----------------------------------------------*/
diff --git a/src/engine/engine_wb.c b/src/engine/engine_wb.c
index 7f9d133..7838415 100644
--- a/src/engine/engine_wb.c
+++ b/src/engine/engine_wb.c
@@ -19,8 +19,9 @@
 #include "engine_debug.h"
 
 static const struct ocf_io_if _io_if_wb_resume = {
-		.read = ocf_write_wb_do,
-		.write = ocf_write_wb_do,
+	.read = ocf_write_wb_do,
+	.write = ocf_write_wb_do,
+	.resume = ocf_engine_on_resume,
 };
 
 static void _ocf_write_wb_update_bits(struct ocf_request *req)
@@ -176,8 +177,7 @@ int ocf_write_wb(struct ocf_request *req)
 	/* Not sure if we need this. */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = ocf_engine_on_resume;
+	/* Set resume io_if */
 	req->io_if = &_io_if_wb_resume;
 
 	/* TODO: Handle fits into dirty */
diff --git a/src/engine/engine_wi.c b/src/engine/engine_wi.c
index 2838d65..832d9b8 100644
--- a/src/engine/engine_wi.c
+++ b/src/engine/engine_wi.c
@@ -130,6 +130,7 @@ static void _ocf_write_wi_on_resume(struct ocf_request *req)
 static const struct ocf_io_if _io_if_wi_resume = {
 	.read = _ocf_write_wi_do,
 	.write = _ocf_write_wi_do,
+	.resume = _ocf_write_wi_on_resume,
 };
 
 int ocf_write_wi(struct ocf_request *req)
@@ -144,8 +145,7 @@ int ocf_write_wi(struct ocf_request *req)
 	/* Get OCF request - increase reference counter */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = _ocf_write_wi_on_resume;
+	/* Set resume io_if */
 	req->io_if = &_io_if_wi_resume;
 
 	OCF_METADATA_LOCK_RD(); /*- Metadata READ access, No eviction --------*/
diff --git a/src/engine/engine_wt.c b/src/engine/engine_wt.c
index f8962ba..df85901 100644
--- a/src/engine/engine_wt.c
+++ b/src/engine/engine_wt.c
@@ -156,8 +156,9 @@ static int _ocf_write_wt_do(struct ocf_request *req)
 }
 
 static const struct ocf_io_if _io_if_wt_resume = {
-		.read = _ocf_write_wt_do,
-		.write = _ocf_write_wt_do,
+	.read = _ocf_write_wt_do,
+	.write = _ocf_write_wt_do,
+	.resume = ocf_engine_on_resume,
 };
 
 int ocf_write_wt(struct ocf_request *req)
@@ -171,8 +172,7 @@ int ocf_write_wt(struct ocf_request *req)
 	/* Get OCF request - increase reference counter */
 	ocf_req_get(req);
 
-	/* Set resume call backs */
-	req->resume = ocf_engine_on_resume;
+	/* Set resume io_if */
 	req->io_if = &_io_if_wt_resume;
 
 	OCF_METADATA_LOCK_RD(); /*- Metadata READ access, No eviction --------*/
diff --git a/src/engine/engine_zero.c b/src/engine/engine_zero.c
index 57dc489..f3d0439 100644
--- a/src/engine/engine_zero.c
+++ b/src/engine/engine_zero.c
@@ -129,6 +129,7 @@ static int _ocf_zero_do(struct ocf_request *req)
 static const struct ocf_io_if _io_if_ocf_zero_do = {
 	.read = _ocf_zero_do,
 	.write = _ocf_zero_do,
+	.resume = ocf_engine_on_resume,
 };
 
 /**
@@ -147,7 +148,6 @@ void ocf_engine_zero_line(struct ocf_request *req)
 
 	ENV_BUG_ON(!ocf_engine_is_mapped(req));
 
-	req->resume = ocf_engine_on_resume;
 	req->io_if = &_io_if_ocf_zero_do;
 
 	/* Some cache line are mapped, lock request for WRITE access */
diff --git a/src/ocf_request.h b/src/ocf_request.h
index b26de96..df9cb3d 100644
--- a/src/ocf_request.h
+++ b/src/ocf_request.h
@@ -131,12 +131,6 @@ struct ocf_request {
 	const struct ocf_io_if *io_if;
 	/*!< IO interface */
 
-	void (*resume)(struct ocf_request *req);
-	/*!< OCF request resume callback */
-
-	ocf_part_id_t part_id;
-	/*!< Targeted partition of requests */
-
 	void *priv;
 	/*!< Filed for private data, context */
 
@@ -167,27 +161,33 @@ struct ocf_request {
 	uint32_t alloc_core_line_count;
 	/*! Core line count for which request was initially allocated */
 
-	ocf_queue_t io_queue;
-	/*!< I/O queue handle for which request should be submitted */
-
 	int error;
 	/*!< This filed indicates an error for OCF request */
 
-	int rw;
+	ocf_part_id_t part_id;
+	/*!< Targeted partition of requests */
+
+	uint8_t rw : 1;
 	/*!< Indicator of IO direction - Read/Write */
 
+	uint8_t d2c : 1;
+	/**!< request affects metadata cachelines (is not direct-to-core) */
+
+	uint8_t dirty : 1;
+	/**!< indicates that request produces dirty data */
+
+	uint8_t master_io_req_type : 2;
+	/*!< Core device request context type */
+
+	ocf_queue_t io_queue;
+	/*!< I/O queue handle for which request should be submitted */
+
 	struct list_head list;
 	/*!< List item for OCF IO thread workers */
 
 	struct ocf_req_info info;
 	/*!< Detailed request info */
 
-	uint8_t d2c;
-	/**!< request affects metadata cachelines (is not direct-to-core) */
-
-	uint8_t master_io_req_type;
-	/*!< Core device request context type */
-
 	void (*complete)(struct ocf_request *ocf_req, int error);
 	/*!< Request completion funstion */
 
diff --git a/src/utils/utils_cleaner.c b/src/utils/utils_cleaner.c
index 0fe500f..29b7d4a 100644
--- a/src/utils/utils_cleaner.c
+++ b/src/utils/utils_cleaner.c
@@ -703,23 +703,22 @@ static int _ocf_cleaner_fire_cache(struct ocf_request *req)
 	return 0;
 }
 
-static const struct ocf_io_if _io_if_fire_cache = {
-		.read = _ocf_cleaner_fire_cache,
-		.write = _ocf_cleaner_fire_cache,
-};
-
 static void _ocf_cleaner_on_resume(struct ocf_request *req)
 {
 	OCF_DEBUG_TRACE(req->cache);
 	ocf_engine_push_req_front(req, true);
 }
 
+static const struct ocf_io_if _io_if_fire_cache = {
+	.read = _ocf_cleaner_fire_cache,
+	.write = _ocf_cleaner_fire_cache,
+	.resume = _ocf_cleaner_on_resume,
+};
+
 static int _ocf_cleaner_fire(struct ocf_request *req)
 {
 	int result;
 
-	/* Set resume call backs */
-	req->resume = _ocf_cleaner_on_resume;
 	req->io_if = &_io_if_fire_cache;
 
 	/* Handle cache lines locks */